ContourHD, one of the better HD sports cams, just got a surfboard mount.
I've been using the GoPro HD cameras in the water, and those mounts have survived horrific wipeouts at the Maverick's big wave contest. These look pretty strong, too. And, unlike the GoPro, they rotate around without having to unbolt the camera, and if you lose the camera, the case floats, too. The waterproof case can also be mounted to "fin or boot holes". Looks great, and it's fantastic to see the arms race between sport camera makers heat up. $40.